Signaling that loud grassroots resistance may be working, congressional Democrats are failing to get behind the White House’s push for unilateral authority over the secretive 12-nation trade deal known as the Trans-Pacific Partnership (TPP), according to news reports on Tuesday.

At issue is whether the House will approve a pending bill that would grant President Barack Obama ‘Fast Track’ trade promotion authority, which would allow the White House to bypass Congress and seal the deal on the controversial TPP.

According to The Hill on Tuesday, as few as 15 House Democrats appear willing to support Fast Track legislation. That number, The Hill reports, is “far fewer than the 50 Democrats Speaker John Boehner (R-Ohio) and other Republicans have asked the White House to deliver.” And with some conservatives wary of backing the President, “it’s possible a vote would fail on the floor.”

A Senate version of Fast Track is currently being negotiated by leaders of the Senate Finance Committee, Sens. Orrin Hatch (R-Utah) and Ron Wyden (D-Ore.), and will reportedly be brought to a hearing on Thursday of this week.

“Fast Track is, in essence, congressional pre-approval” of the TPP, notes Dave Johnson, fellow at the Campaign for America’s Future. “With Fast Track Congress agrees to give up its much of constitutional duty to define negotiating objectives, carefully deliberate and debate, and fix problems that might turn up.”

And critics say that such problems are many. The largest trade agreement to be negotiated by the U.S. in more than a decade, opponents charge that the pact will pave the way for greater corporate malfeasance while threatening the environment, food and health safety standards, workers rights, and access to medicine worldwide.

On Monday, Reuters reported that Japanese and U.S. officials are meeting next week to discuss the trade deal and are banking on fast track approval to ease those talks.